1. Field of the Invention
The present invention relates to a three-dimensional shape measuring system and a three-dimensional shape measuring method for measuring the three-dimensional shape of an object.
2. Description of the Related Art
One of various methods for measuring the three-dimensional shape of an object, e.g., a surface defect or smoothness of a coated surface on a workpiece or the like, is known as a TOF (Time Of Flight) method, which utilizes pulsed light.
According to such a TOF method using pulsed light, pulsed light emitted from a pulsed light source is reflected by an irradiated region on a surface of an object, and then the reflected light is detected by a detector. Based on the times of flight (TOF) that the pulsed light takes until it is detected by the detector, as well as on the velocity of light, depthwise distance differences are calculated in order to measure the three-dimensional shape on the surface of the object.
Japanese Patent No. 2500379 discloses a three-dimensional shape measuring apparatus, which converts three-dimensional information into a colored contour map in the form of a two-dimensional image, and detects the three dimensional information using light pulses, the color of which changes regularly with time, i.e., so-called chirped light pulses. The disclosed three-dimensional shape measuring apparatus is capable of measuring the three-dimensional shape of an object highly accurately at a high speed.
However, although the three-dimensional shape measuring apparatus disclosed in Japanese Patent No. 2500379 is able to measure the three-dimensional shape of an object highly accurately, a region (area) irradiated by the pulsed light needs to be established within a small space in order to achieve the desired level of measurement accuracy. Therefore, the disclosed three-dimensional shape measuring apparatus is problematic, in that the region which can be measured in one irradiation cycle, i.e., the measured region, is limited.